Supplementary support for vehicles

ABSTRACT

A removable frame for reduction of axle loads for heavy vehicles is disclosed herein. The frame includes a pair of lever arms pivoted to each other at one end with adjustable biasing means between the free ends of the lever arms. One of the lever arms has at least one wheel supported thereon while the other arm is rotatably connected to a support member adapted to be attached to a vehicle frame. A centering mechanism normally maintains the lever arm in a predetermined position on the support member and accommodates rotation with respect to each other.

BACKGROUND OF THE INVENTION

The invention relates to a mobile frame for the reduction of the axleloads of heavy vehicles, comprising at least one rotor wheel and onesupporting member.

In construction machines, such as dredges, concrete mixers or the like,as well as in farm machinery, it is known to provide mobile frames onthe vehicle frames which only are placed in contact with the roadsurface if and when the machines are to be moved over greater distancesor if loads are higher than under normal operations. By using the mobileframes the loads upon the remaining axles are reduced and particularlyon bridges and in case of insufficiently solidified ground thedistribution of the load becomes more uniform. The mobile frames fixedlyarranged at the vehicle frame, however, demand considerable constructiveexpenses and must remain permanently at the vehicle, although they areused relatively rarely. That is why the system of placing heavyconstruction machinery on flat-bed trailers, when it is to be hauledover major distances has been maintained. However, this produces twoadditional disadvantages, because as a rule a flat-bed trailer must berequisitioned and thus it is not available at all times and modernconstruction machines frequently are so high that in case of lowunderpasses, as they can be encountered precisely in the country,problems may arise which require considerable detours.

Consequently, the present invention is based on the problem ofeliminating these disadvantages and to create a mobile frame which isinexpensive, adaptable and easy to handle.

SUMMARY OF THE INVENTION

In order to solve this problem, it is proposed with regard to the mobileframe described initially and according to the present invention, thatit is provided with two lever arms interconnected by means of anarticulation or pivotal connection. A trigger or biasing mechanism isarranged between their free ends, with one of the levers having asupporting member connected to the frame of the vehicle, and the otherlever supporting at least one axle with at least one rotor wheel.

The mobile frame so designed is a simple, compact apparatus which can bearranged at any appropriate location beneath the frame. For example, incase of dragline vehicles it may be arranged between the dragline unitand the motor unit in such a fashion that it grips below the crossbeamwhich on the one hand bears both arms for the positioning of thedragline bucket and on the other hand the supporting arm for connectingthe dragline unit to the motor unit. Two mobile frames are appropriatelyarranged below the crossbeam. Advantageously they are designed aspendulum roller frames by positioning the supporting member at theupper, substantially horizontal lever arm about a vertical shaft in arotatable manner. That way the mobile frames are self-adjusting to thedirection of travel and the vehicle can be steered in the usual manner.

In case of heavy dragline vehicles about 55% repose on the axle of themotor unit and about 45% of the entire load repose on the axle of thedragline unit. Two mobile frames below the crossbeam can handle about28% of the total load. At the same time the axle load at the motor unitis reduced to about 37%, and the one at the dragline unit to about 35%.Thus, the entire load is distributed in the range between 28% and 37%substantially more uniformly than without the use of one or two mobileframes, so that a correpondingly more uniform load results on bridges orunfavorable ground likewise.

The mobile frames may remain in the depot and thus they are protectedagainst contamination and damage as same occur precisely in the case ofdragline vehicles. They only are used whenever one of the draglinevehicles is to be moved to a different point of operation or into theshop. They can be used for different vehicles and the supporting elementor member may be designed with corresponding adjustability.

An embodiment of the invention is exemplified in the drawing andexplained more in detail in the following specification.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows the mobile frame in lateral view with one axle and tworotor wheels, from which one wheel has been removed, and

FIG. 2 shows the mobile frame in a top view with the supporting memberremoved.

DETAILED DESCRIPTION

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawings and will herein be described indetail a preferred embodiment of the invention with the understandingthat the present disclosure is to be considered as an exemplification ofthe principles of the invention and is not intended to limit theinvention of the embodiment illustrated.

Substantially, the mobile frame comprises two lever arms 10 and 11, bothof which are designed as toggle levers. The upper lever arm 10 has asubstantially horizontal leg 12 and a substantially vertical leg 14.Correspondingly, the lower lever arm 11 has a horizontal leg 13 and avertical leg 15. Both vertical legs 14 and 15 are interconnectedpivotably by a bearing or pivot pin 16. A trigger or biasing means 17 isarranged between the free ends of the horizontal legs 12 and 13.

A bearing block 18 for supporting a shaft or axle 19 is located on thebottom side of the horizontal leg 13 of the lower lever arm 11. Rotorwheels 20 are positioned in overhung position on both sides of thehorizontal leg 13 on said shaft 19.

With the use of a powerful pressure spring (not shown) the trigger orbiasing means 17 is so designed that it has a tendency of separatingboth horizontal legs 12 and 13 about the pivot pin. This is limited by acatch strap or limiting means 21 which at 22 is fastened to thehorizontal leg 12 and placed about the shaft 19. The catch strap 21 doesnot impede the movement of the leg 12 in the direction of the leg 13 asthe loads are being applied.

A bearing 23, in which a substantially vertical shaft 24 of a supportingmember 25 is guided, is provided on the horizontal leg 12 of the leverarm 10. Appropriately, the bearing 23 is provided with at least oneroller bearing, so that the supporting member 25 is easily rotatableabout a vertical axis with reference to the leg 12. The supportingmember 25 is provided with a connecting plate 26 which may be equippedwith perforations 27, so that the connecting plate 26 can be connectedto the cross bar, for example, of a dragline vehicle. A mounting platecorresponding to the connecting plate 26 may be provided at the crossbar. At least one spacer means may be arranged between the mountingplate and the connecting plate 26. However, the possibility also existsto arrange the supporting member 25 vertically adjustably at the shaft24. Likewise, in place of the connecting plate 26 the supporting member25 may be provided with a fork, into which a cross bar, rib or the likeof the frame of a vehicle can be inserted. The supporting member alsomay be provided with two back-to-back forks which grip below adjacentcross bars, ribs or the like.

In the exemplified embodiment, the supporting member 25 has cooperatingmeans for limiting rotatability of the levers with respect to shaft 24.The limiting means includes a sector-shaped disc 28 extending radiallyfrom the shaft 24 for rotation therewith and is provided at its freeperipheral edge with an arcuate cam track 29. The cam track 29 has,pointing in longitudinal direction of the mobile frame, a centralindentation 30 which forms a continuation of the cam track 29 and has acentral root 31. The cam track 29 extends over a circular arc of about120° and its ends are followed by terminal sections 39.

A bracket 32 with a bearing pin 33 is fastened to the horizontal leg 12of the upper lever arm 10, laterally above the fastening point 22. Alever 34 is pivoted on the pin 33, with a piston 35 of an operatingcylinder 36 attached to the free end of lever 34 and piston 35 is biasedto an extended position. Approximately in the center of the lever 34 abearing 37 supports a cam roller 38 which is biased toward the cam track29. On a straight path for the vehicle the cam roller 38 is located inthe root 31 of the indentation 30. In this position the cam roller 38 ismaintained by the operating cylinder 36, whereby the piston rod 35 canescape backward resiliently. This resiliency can be adjusted constantlyby a spring or it may be variable by the pneumatic flow medium, which issupplied to the operating cylinder and piston assembly 36 via a conduit40. A control valve (not shown) which so adjusts the pressureimpingement that the cam roller 38 cannot leave the indentation 30, maybe provided in the feed conduit 40.

If the force of the fluid medium or the spring is exceeded by turningforces on wheels 20, the wheels can turn and accommodate turningmovement of the frame supported thereon.

Another pneumatic flow medium conduit 41 leads to the biasing means ortrigger 17 which has a pressure spring (not shown) in the exemplifiedembodiment and is enveloped by a bellows which is impermeable for theflow medium. A control and/or superpressure valve, likewise not shown,is placed in the flow medium conduit 41. The force of the spring can bereinforced by pneumatic pressure impingement of the trigger 17, so thatan increased expanding pressure acts between the horizontal legs 12 and13 of the lever arms 10 and 11. At the same time the load capacity ofthe mobile frame increases accordingly. Thus, it can further relieve,for example, in case of dragline vehicle the axle of the dragline unitand that of the motor unit still further. The cross bar of the draglineunit can be engaged in a most simple fashion with the connecting plate26 of one or two roller frames, by lowering the dragline unit from itstopmost position in the direction of its operating position by a certainamount, until the admissible load capacity of the mobile frame has beenreached. Unevennesses of the ground or of roads cause shocks to theroller frame, but they are absorbed by the trigger or latch 17 and thesuperpressure valve in conduit 41.

The mobile frame is usable particularly in case of rubber-tired flatbeddredges for transfers on public roadways and causes a uniformdistribution of the loads on the wheel axles, particularly withtransverse and if necessary longitudinal stabilization.

What is claimed is:
 1. A removable mobile frame for reduction of axleloads of a heavy vehicle comprising first and second horizontal leverarms pivotally interconnected at one end, biasing means interposedbetween free ends of said lever arms, a supporting member connected tosaid first lever arm and adapted to be attached to said vehicle, theconnection between said supporting member and said first lever armincluding a shaft defining a vertical rotatable pivot axis between saidfirst lever arm and said supporting member, means normally maintainingsaid supporting member and said first lever arm in a predeterminedposition and accommodating rotation from said predetermined position,said last means including a cam track on said supporting member and acam on said first lever arm biased into engagement with said cam trackwith said cam track defining said predetermined position, and at leastone axle and one rotor wheel on said axle connected to said second leverarm.
 2. A mobile frame as defined in claim 1, further including meansfor varying the biasing force on said cam.
 3. A mobile frame as definedin claim 1, further including means for varying the biasing force ofsaid biasing means between said lever arms.
 4. A mobile frame as definedin claim 3, in which said means for varying the biasing force includes acylinder and piston assembly and means for supplying pneumatic fluid tosaid assembly.
 5. A mobile frame as defined in claim 1, in which saidaxle has a pair of wheels at opposite ends thereof located on oppositesides of said lever arms.
 6. A mobile frame as defined in claim 5,further including limiting means defining an extreme biased position forsaid lever arms.